European Journal of Oral Implantology最新文献

Purpose: To ascertain whether in the presence of a previously endodontically treated tooth with a periapical pathology and/or symptoms and an uncertain prognosis, it is better to endodontically retreat it or to replace the tooth with a single implant-supported crown.

Materials and methods: Forty patients requiring the treatment of a previously endodontically treated tooth, with a periapical pathology and/or symptoms of endodontic origin and an uncertain prognosis, as judged by the recruiting investigators, were randomly allocated to endodontic retreatment (endo group; 20 patients) or tooth extraction and replacement with an implant-supported crown (implant group; 20 patients) according to a parallel group design at two different centres. Patients were followed to 1 year after completion of the treatment. Outcome measures were: failure of the procedure, complications, marginal bone level changes at both teeth and implants, endodontic radiographic success (teeth only), number of patients' visits and days to complete the treatment, patients' chair time, costs, aesthetics assessed using the pink esthetic score (PES) for the soft tissues and the white esthetic score (WES) for the tooth/crown recorded by independent assessors.

Results: No patient dropped out and no complications occurred during the entire follow-up; however, one endodontically retreated tooth (5%) and one implant (5%) fractured, the difference for treatment failures being not statistically significant (difference in proportions = 0; 95% CI -0.14 to 0.14; P Fisher's exact test) = 1.000). The mean marginal bone levels at endo retreatment/implant insertion were 2.34 ± 0.88 mm for the endo and 0.23 ± 0.35 mm for the implant group, which was statistically significantly different (mean difference = 2.11 mm; 95% CI: 1.68 to 2.55; P (t-test) < 0.001). One year after completion of the treatment, teeth lost on average 0.32 ± 0.53 mm and implants 0.48 ± 0.72, the difference not being statistically significant (mean difference = -0.16 mm; 95% CI: -0.58 to 0.27; P (t-test) = 0.457). One year after completion of the endodontic retreatment, of the 13 teeth that originally had a periapical radiolucency, one was lost, six showed complete healing; four a radiographic improvement; and two showed no changes/worsening. Two of the teeth originally without a lesion developed a lesion. There were no statistically significant differences for the number of patients' visits (endo = 5.2 ± 1.8; implant = 5.5 ± 1.1; mean difference = -0.03 95% CI: -1.24 to 0.64; P (t-test) = 0.522). It took significantly more days to complete the implant rehabilitation (endo = 48.9 ± 19.5; implant = 158.5 ± 67.2; mean difference = -109.60; 95% CI: -141.26 to -77.94; P (t-test) < 0.001), but less patients' chair time (endo = 405.5 ± 230.3 min; implant = 260.0 ± 154.6 min; mean difference = 45.50; 95% CI: 19.35 to 271.65; P (t-test) = 0.025). Implant treatment was sign

Purpose: To evaluate the ultra-low dose scanning protocols of a newly developed CBCT for pre-implant radiographic assessment.

Materials and methods: A total number of 32 CBCT scans were exposed at 90 kV using ProMax 3D's standard (GS) and three ultra-low dose scanning protocols: high, mid and low definition (UL-HD, UL-MD and UL-LD) on eight human dry skulls with simulated soft tissue. The mAs values and the voxel size were 96mAs/200 µm, 28mAs/150 µm, 22.4mAs/200 µm and 7.5mAs/400 µm for scanning protocols GS, UL-HD, UL-MD and UL-LD, respectively. The overall image quality and the precision of anatomical landmarks were assessed on a 4-rank ordinal scale by seven observers. Logistic regression analysis and post-hoc Scheffé test were applied to analyse possible differences in image quality and recognition of the anatomical structures for the three ultra-low dose protocols, compared with the standard protocol. Additionally, observers performed bone quality assessment and bone quantity measurement at 96 predefined 2D cross-sectional images. A Pearson Chi-square test and a paired t-test were used to analyse assessed bone quality and quantity using the four scanning protocols respectively.

Results: For the CBCT unit, ProMax 3D, UL-LD was not diagnostically acceptable for pre-implant assessment, whereas the UL-HD and UL-MD were diagnostically acceptable regarding overall image quality, visibility of most anatomical structures and bone quality assessment. However, to recognise the border of mandibular canal and the border of maxillary sinus, standard protocol may be indicated for some cases. No statistically significant differences in bone height measurement were found when applying standard protocol and the three ultra-low dose protocols.

Conclusions: Low-dose scanning protocols may be applied for pre-implant radiographic assessment, although image quality can be hampered if the radiation exposure is too low and the voxel size too large.

Aim: To compare implant fixed complete dentures with implant overdentures relative to prosthodontic outcomes.

Material and methods: An electronic Medline (PubMed) with MeSH terms, and Cochrane library search was performed, focusing on studies that included implant fixed complete dentures and implant overdentures in the same study, with the results based on studies that included both types of prostheses.

Results: The following six categories of comparative studies were identified in the literature: 1) Implant and prosthesis survival; 2) Prosthesis maintenance/complications; 3) Bone changes; 4) Patient satisfaction and quality of life; 5) Cost-effectiveness; and 6) Masticatory performance. It was determined that both the fixed and removable treatments were associated with high implant survival rates. However, both types of prostheses were impacted by the need for post-placement mechanical maintenance or prosthetic complications. More maintenance/complications occurred with implant overdentures than with fixed complete dentures. Residual ridge resorption was greater with implant overdentures. Patient satisfaction was high with each prosthesis, with three studies revealing higher satisfaction with fixed complete dentures and five studies finding no difference. All but one study on cost-effectiveness indicated implant overdentures were more cost-effective. Based on two studies, it appears the masticatory performance of implant fixed complete dentures and implant overdentures is comparable.

Conclusions: Multiple factors must be considered when determining whether an implant-fixed complete denture or implant overdentures are best suited for patients with completely edentulous jaws. Conflict-of-interest statement: The authors declare they have no conflicts of interest.

Purpose: To evaluate the outcome of two vs four implants placed flapless in fully edentulous mandibles and immediately restored with metal-resin screw-retained cross-arch prostheses.

Materials and methods: A total of 60 patients from two different centres were randomised: 30 to the fixed-on-2 group and 30 to the fixed-on-4 group according to a parallel group design. To be immediately loaded implants had to be inserted with a minimum torque of 40 Newton/cm (Ncm). Outcome measures were prosthesis and implant failures, complications, and marginal bone level changes.

Results: Flaps were raised in 18 patients. Two implants in two patients did not reach the planned insertion torque and were replaced immediately by larger diameter ones. Three years after loading, two patients dropped out from the fixed-on-2 group and one from the fixed-on-4 group. No implant failure or prosthetic failure occurred. A total of 12 fixed-on-2 patients were affected by one complication each vs 13 fixed-on-4 patients. There were no statistically significant differences for complications between groups (difference in proportion = -0.03; 95% CI -29 to 0.22; P [Fisher's exact test] =1.000). There were no statistically significant differences for marginal peri-implant bone loss between the two groups (mean difference = 0.14; CI 95% -0.17 to 0.45; P [ANCOVA] = 0.356), with both groups losing marginal bone in a statistically significant way (1.70 mm for fixed-on-2 implants and 1.56 mm for fixed-on-4 implants). There were statistically significant differences between the two centres, with more bone being lost for the Bologna centre (2.18 vs 1.13 mm; P (ANCOVA) < 0.001).

Conclusions: Up to 3 years after loading, these preliminary results suggest that immediately loaded mandibular cross-arch fixed prostheses can be supported by only two dental implants. Longer follow-ups (about 10 years) are needed to properly evaluate this therapeutic option. Conflict of interest statement: This study was completely self-financed and no funding from the implant manufacturers has been sought or obtained, not even in the form of free materials.

Purpose: To compare the clinical and radiological outcomes of identical implants with conical or internal hex connections.

Methods: A total of 90 patients with partial edentulism requiring one implant-supported prosthesis were randomly allocated in two equal groups (n = 45) to receive either implants with a conical connection or implants of the same type, but with an internal hex connection at three centres. Patients were followed for 1 year after loading. Outcome measures were implant failures, any complication and marginal bone level changes.

Results: One patient (2.2%) belonging to the internal hex group dropped out. One implant (2.2%) failed in the conical group. There were no statistically significant differences in implant failures between the two groups (2.2% vs. 0%, difference 2.2; 95% CI: -1.3; 5.7; P = 0.315). Two complications occurred in the conical group and two in the internal hex group (P = 1.000, difference 0.00, 95% CI: -3.1; 3.1). The 12-month peri-implant bone resorption was similar in both groups: 0.56 ± 0.53 mm (95% CI 0.03; 1.09) in the conical group and 0.60 ± 0.62 mm (95% CI 0.02; 1.22) in the internal hex group (difference = 0.04 ± 0.55, 95% CI: -0.51; 0.59, P = 0.745).

Conclusions: Within the limitation of this study, preliminary short-term data (1 year post-loading) did not show any statistical differences between the two internal connection types, therefore clinicians could choose whichever connection they prefer. Conflict of interest statement: Tommaso Grandi serves as consultant for J Dental Care, Modena, Italy. This study was completely self-financed and no funding was sought or obtained, not even in the form of free materials.

Purpose: The objectives of this two-period, crossover, mono-centred, double-blind, randomised controlled trial (RCT) were to compare two different materials used for full arch implant-supported prosthetic restorations with regard to patient preference and impact on a patient's quality of life.

Materials and methods: Edentulous patients requesting one full arch restoration in the mandible or maxilla supported by dental implants were included in this study. Patients were randomised to receive either a full arch zirconia framework hand-veneered with ceramic, or a full arch zirconia framework hand-veneered with composite material. After 1 month, the first randomised restoration was substituted by the other, which was left in function for a further observation period of 1 month. Outcome measures were: patient preference and satisfaction (OHIP-21), complications, visual analogue scales for chewing comfort, aesthetic acceptance, phonetic comfort, full mouth plaque score (FMPS).

Results: Twenty-four patients were randomised to the treatments in the two periods. There was one dropout. At the end of the study, 16 patients (70%) preferred to wear ceramic prosthesis and 7 patients (30%) preferred to wear composite prosthesis (ceramic preference: 70%; 95%CI from 47 to 87%; P = 0.0605). Difference in OHIP-21 reduction between the two treatments was not significant (difference 0.5, 95%CI from -2.8 to 3.8, P = 0.7788). There was one minor complication during the ceramic period in one patient and one minor complication during the composite period in another patient (odds ratio 1.00, 95%CI from 0.06 to 15.99, P = 1.0). The difference in FMPS between treatments was not significant (0.5, 95%CI from -1.3 to 2.2, P = 0.5731). Difference in VAS between the two treatments was not significant for general satisfaction (P = 0.2067), chewing comfort (P = 0.8345) and phonetics (P = 0.9167). Difference in VAS between the two treatments was significant for aesthetic acceptance favouring the ceramic prosthesis (difference 0.9, 95%CI from 0.006 to 1.8, P = 0.0486).

Conclusions: No difference between the two treatments was detected for preference, changes of OHIP-21, complications, reduction of FMPS, VAS changes regarding patient satisfaction, chewing and phonetics. Nevertheless, a slight difference was detected in the VAS regarding aesthetic acceptance favouring the ceramic material.

Funding: The study was supported by Nobel Biocare (grant 2012-1077). Thanks to this contribution, the patients who consented to participate in this RCT were not charged for the material provided by Nobel Biocare. In addition, the patients benefited from a further back-up prosthesis that was provided to them completely free of charge.

Aim: The primary aim of this systematic review was to study the clinical outcomes of one-piece fixed complete dentures (complete arch fixed implant-supported prostheses) made of zirconia for edentulous patients. The secondary aim was to compare the clinical outcomes of monolithic zirconia vs zirconia veneered with porcelain (conventional, minimal or gingival) for fixed complete dentures.

Materials and methods: Two investigators conducted an independent electronic search of the literature, using PubMed and Scopus search engines from January 1, 2000, to August 31, 2016. After application of pre-determined inclusion and exclusion criteria, the final list of articles was reviewed to meet the aims of this review.

Results: A total of 12 observational studies were identified that satisfied the inclusion criteria of this systematic review. Short-term results from a combined 223 patients with 285 one-piece zirconia fixed complete dentures showed a mean failure rate of 1.4% due to the fracture of four prostheses. Prosthetic complications occurred in 46 prostheses (16.1%). Out of these, 42 prostheses (14.7%) had minor complications exclusive to fracture of veneered porcelain.

Conclusions: Current evidence indicates that zirconia fixed complete dentures have a very low failure rate in the short term, but have a substantial rate of minor complications related to chipping of veneered porcelain. Use of monolithic zirconia with only gingival stains, or zirconia that is veneered only at the gingiva may offer promising results, but will need to be validated by future long-term studies. Conflict-of-interest statement: All authors report no conflict of interest.

Statement of problem: Zygomatic implants have been utilised for the treatment of the severely atrophic maxilla since 1998. However, few articles exist as to the success of zygomatic implants and immediate loading of its prosthesis.

Aim: To systematically review the outcome of immediate loaded zygomatic implants.

Materials and methods: An electronic PubMed search was performed to identify case reports, prospective and retrospective studies of immediately loaded zygomatic implants with a mean follow-up of 12 months. Assessment of the identified studies was performed using the Delphi method. Reviewers independently assessed the articles for inclusion, with a facilitator coordinating responses. A consensus was reached on the articles that were included.

Results: The search provided 236 titles for immediately loaded zygomatic implants and resulted in 106 abstracts for analysis. Full-text analysis was performed on 67 articles, resulting in the inclusion of 38 articles for this systematic review.

Conclusion: Based on the present systematic review, the authors report that immediately loading zygomatic implants for the restoration of the severely atrophic maxilla presents a viable alternative for treatment of the atrophic maxilla.